class Student(object):
    count = 0

    def __init__(self,name):
        self.name = name
        # 每创建一个实例，属性自动增加
        Student.count += 1


print(Student.count)
a = Student('A')
print(Student.count)
print(a.name)

b = Student('B')
c = Student('C')
print(Student.count)

